The wastelands is the final area of the game (it is a one way trip there).
I don't think mithril is the cause of the high price. The bow merchant in the elven village sometimes has mithril plate armour for sale at reasonable prices. Due to low requirements with a relatively high armour class, this is sometimes favoured my people playing mage characters (as long as they are not sticking too close to the traditional mage build).
